Abstract:
Background:Methane, a main component of natural gas and biogas, has gained much attention as an abundant and low-cost carbon source. Methanotrophs, which can use methane as a sole carbon and energy source, are promising hosts to produce value-added chemicals from methane, but their metabolic engineering is still challenging. In previous attempts to produce lactic acid (LA) from methane, LA production levels were limited in part due to LA toxicity. We solved this problem by generating an LA-tolerant strain, which also contributes to understanding novel LA tolerance mechanisms. Results:In this study, we engineered a methanotroph strain Methylomonas sp. DH-1 to produce d-lactic acid (d-LA) from methane. LA toxicity is one of the limiting factors for high-level production of LA. Therefore, we first performed adaptive laboratory evolution of Methylomonas sp. DH-1, generating an LA-tolerant strain JHM80. Genome sequencing of JHM80 revealed the causal gene watR, encoding a LysR-type transcription factor, whose overexpression due to a 2-bp (TT) deletion in the promoter region is partly responsible for the LA tolerance of JHM80. Overexpression of the watR gene in wild-type strain also led to an increase in LA tolerance. When d form-specific lactate dehydrogenase gene from Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293 was introduced into the genome while deleting the glgA gene encoding glycogen synthase, JHM80 produced about 7.5-fold higher level of d-LA from methane than wild type, suggesting that LA tolerance is a critical limiting factor for LA production in this host. d-LA production was further enhanced by optimization of the medium, resulting in a titer of 1.19 g/L and a yield of 0.245 g/g CH4. Conclusions:JHM80, an LA-tolerant strain of Methylomonas sp. DH-1, generated by adaptive laboratory evolution was effective in LA production from methane. Characterization of the mutated genes in JHM80 revealed that overexpression of the watR gene, encoding a LysR-type transcription factor, is responsible for LA tolerance. By introducing a heterologous lactate dehydrogenase gene into the genome of JHM80 strain while deleting the glgA gene, high d-LA production titer and yield were achieved from methane.
journal_name
Biotechnol Biofuelsjournal_title
Biotechnology for biofuelsauthors
Lee JK,Kim S,Kim W,Kim S,Cha S,Moon H,Hur DH,Kim SY,Na JG,Lee JW,Lee EY,Hahn JSdoi
10.1186/s13068-019-1574-9subject
Has Abstractpub_date
2019-09-30 00:00:00pages
234issn
1754-6834pii
1574journal_volume
12pub_type
杂志文章abstract:BACKGROUND:Cellulose amorphogenesis, described as the non-hydrolytic "opening up" or disruption of a cellulosic substrate, is becoming increasingly recognized as one of the key steps in the enzymatic deconstruction of cellulosic biomass when used as a feedstock for fuels and chemicals production. Although this process ...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/1754-6834-5-51
更新日期:2012-07-24 00:00:00
abstract:BACKGROUND:Bioaugmentation or an addition of the desired microorganisms or specialized microbial strains into the anaerobic digesters can enhance the performance of microbial community in the hydrogen production process. Most of the studies focused on a bioaugmentation of native microorganisms capable of producing hydr...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-015-0375-z
更新日期:2015-11-25 00:00:00
abstract:Background:Lignin is a heterogeneous polymer representing a renewable source of aromatic and phenolic bio-derived products for the chemical industry. However, the inherent structural complexity and recalcitrance of lignin makes its conversion into valuable chemicals a challenge. Natural microbial communities produce bi...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-018-1073-4
更新日期:2018-03-22 00:00:00
abstract:Background:Microalgae are attracting much attention as a promising feedstock for renewable energy production, while simultaneously providing environmental benefits. So far, comparison studies for microalgae selection for this purpose were mainly based on data obtained from batch cultures, where the lipid content and th...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-019-1461-4
更新日期:2019-05-11 00:00:00
abstract:UNLABELLED: BACKGROUND:Acetoin is an important bio-based platform chemical. However, it is usually existed as a minor byproduct of 2,3-butanediol fermentation in bacteria. RESULTS:The present study reports introducing an exogenous NAD+ regeneration sysytem into a 2,3-butanediol producing strain Klebsiella pneumoniae ...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/1754-6834-6-7
更新日期:2013-01-25 00:00:00
abstract:BACKGROUND:Solid-state anaerobic digestion (SS-AD) has been increasingly used for lignocellulosic biomass treatment. However, the separate reactor required for pretreatment prior digestion, poor treatment capacity, and process stability inhibit further development of the SS-AD. In this study, a novel method called SS-A...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-016-0530-1
更新日期:2016-06-01 00:00:00
abstract:Background:Functional sugar alcohols have been widely used in the food, medicine, and pharmaceutical industries for their unique properties. Among these, erythritol is a zero calories sweetener produced by the yeast Yarrowia lipolytica. However, in wild-type strains, erythritol is produced with low productivity and yie...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-020-01815-8
更新日期:2020-10-20 00:00:00
abstract:Background:Part-stream low-frequency ultrasound (LFUS) was one of the common practices for sludge disintegration in full-scale anaerobic digestion (AD) facilities. However, the effectiveness of part-stream LFUS treatment and its effect on AD microbiome have not been fully elucidated. Methods:Here we testified the effe...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-018-1042-y
更新日期:2018-02-21 00:00:00
abstract:Background:Biofilms are cell communities wherein cells are embedded in a self-produced extracellular polymeric substances (EPS). The biofilm of Clostridium acetobutylicum confers the cells superior phenotypes and has been extensively exploited to produce a variety of liquid biofuels and bulk chemicals. However, little ...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-018-1316-4
更新日期:2018-11-20 00:00:00
abstract:BACKGROUND:The model alga Chlamydomonas reinhardtii requires acetate as a co-substrate for optimal production of lipids, and the addition of acetate to culture media has practical and economic implications for algal biofuel production. Here we demonstrate the growth of C. reinhardtii on acetate provided by mutant strai...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-014-0154-2
更新日期:2014-10-18 00:00:00
abstract:BACKGROUND:Low cost of raw materials and good process yields are necessary for future lignocellulosic biomass biorefineries to be sustainable and profitable. A low cost feedstock will be diverse, changing as a function of seasonality and price and will most likely be available from multiple sources to the biorefinery. ...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-015-0414-9
更新日期:2015-12-24 00:00:00
abstract:Background:With the further development of anaerobic digestion, an increasing output of anaerobically digested wastewater (ADW), which typically contained high concentrations of ammonium, phosphate, and suspended solids, was inevitable. Microalgae cultivation offered a potential waste-to-value strategy to reduce the hi...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-018-1190-0
更新日期:2018-07-09 00:00:00
abstract:BACKGROUND:In addition to efficient pentose utilization, high inhibitor tolerance is a key trait required in any organism used for economically viable industrial bioethanol production with lignocellulose biomass. Although recent work has succeeded in establishing efficient xylose fermentation in robust industrial Sacch...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/1754-6834-6-120
更新日期:2013-08-26 00:00:00
abstract:BACKGROUND:Reduced yields of ethanol due to bacterial contamination in fermentation cultures weaken the economics of biofuel production. Lactic acid bacteria are considered the most problematic, and surveys of commercial fuel ethanol facilities have found that species of Lactobacillus are predominant. Bacteriophage lyt...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/1754-6834-6-20
更新日期:2013-02-07 00:00:00
abstract:BACKGROUND:Microbial synthesis of oleochemicals derived from native fatty acid (FA) metabolism has presented significant advances in recent years. Even so, native FA biosynthetic pathways often provide a narrow variety of usually linear hydrocarbons, thus yielding end products with limited structural diversity. To over...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-016-0631-x
更新日期:2016-10-14 00:00:00
abstract:BACKGROUND:Engineering of the yeast Saccharomyces cerevisiae for improved utilization of pentose sugars is vital for cost-efficient cellulosic bioethanol production. Although endogenous hexose transporters (Hxt) can be engineered into specific pentose transporters, they remain subjected to glucose-regulated protein deg...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-016-0573-3
更新日期:2016-07-26 00:00:00
abstract:BACKGROUND:In general, biofuel production involves biomass pretreatment and enzymatic saccharification, followed by the subsequent sugar conversion to biofuel via fermentation. The crucial step in the production of biofuel from biomass is the enzymatic saccharification. Many of the commercial cellulase enzyme cocktails...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-016-0587-x
更新日期:2016-08-22 00:00:00
abstract:Background:Propionic acid (PA), a key platform chemical produced as a by-product during petroleum refining, has been widely used as a food preservative and an important chemical intermediate in many industries. Microbial PA production through engineering yeast as a cell factory is a potentially sustainable alternative ...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-019-1427-6
更新日期:2019-04-23 00:00:00
abstract:BACKGROUND:Recent studies have demonstrated that microalga has been widely regarded as one of the most promising raw materials of biofuels. However, lack of an economical, efficient and convenient method to harvest microalgae is a bottleneck to boost their full-scale application. Many methods of harvesting microalgae, ...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/1754-6834-6-98
更新日期:2013-07-09 00:00:00
abstract:BACKGROUND:The production of value-added chemicals alongside biofuels from lignocellulosic hydrolysates is critical for developing economically viable biorefineries. Here, the production of propionic acid (PA), a potential building block for C3-based chemicals, from corn stover hydrolysate is investigated using the nat...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-017-0884-z
更新日期:2017-08-17 00:00:00
abstract:Background:Beer is the most popular alcoholic beverage worldwide. In the manufacture of beer, various by-products and residues are generated, and the most abundant (85% of total by-products) are spent grains. Thanks to its high (hemi)cellulose content (about 50% w/w dry weight), this secondary raw material is attractiv...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-019-1383-1
更新日期:2019-03-05 00:00:00
abstract:Background:Cellulolytic enzymes produced by Trichoderma reesei are widely used for the industrial production of biofuels and chemicals from lignocellulose. We speculated that intracellular pH during the fermentation process can affect cellulase induction. Results:In this study, two H+-ATPase genes, tre76238 and tre787...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-019-1536-2
更新日期:2019-08-13 00:00:00
abstract:BACKGROUND:P450 fatty acid decarboxylases represented by the unusual CYP152 peroxygenase family member OleTJE have been receiving great attention recently since these P450 enzymes are able to catalyze the simple and direct production of 1-alkenes for potential applications in biofuels and biomaterials. To gain more mec...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-017-0894-x
更新日期:2017-09-07 00:00:00
abstract:Background:Microalgae are efficient producers of lipid-rich biomass, making them a key component in developing a sustainable energy source, and an alternative to fossil fuels. Chlorella species are of special interest because of their fast growth rate in photobioreactors. However, biological constraints still cast a si...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-019-1566-9
更新日期:2019-09-16 00:00:00
abstract:BACKGROUND:Isobutanol can be a better biofuel than ethanol due to its higher energy density and lower hygroscopicity. Furthermore, the branched-chain structure of isobutanol gives a higher octane number than the isomeric n-butanol. Saccharomyces cerevisiae was chosen as the production host because of its relative toler...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/1754-6834-4-21
更新日期:2011-07-28 00:00:00
abstract:BACKGROUND:The production of biofuels in photosynthetic microalgae and cyanobacteria is a promising alternative to the generation of fuels from fossil resources. To be economically competitive, producer strains need to be established that synthesize the targeted product at high yield and over a long time. Engineering c...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/1754-6834-7-21
更新日期:2014-02-06 00:00:00
abstract:Background:Phototrophic purple non-sulfur bacteria (PNSB) have gained attention for their ability to produce a valuable clean energy source in the form biohydrogen via photofermentation of a wide variety of organic wastes. For maturation of these phototrophic bioprocesses towards commercial feasibility, development of ...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-020-01743-7
更新日期:2020-06-09 00:00:00
abstract:BACKGROUND:Considerable works have been reported concerning the obstruction of enzymatic hydrolysis efficiency by lignin. However, there is a lack of information about the influence of lignin on the adsorption of cellulases on cellulose, along with the hydrolytic activity of the cellulases adsorbed on lignin. In additi...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-016-0434-0
更新日期:2016-01-26 00:00:00
abstract:Background:As a renewable carbon source, biomass energy not only helps in resolving the management problems of lignocellulosic wastes, but also helps to alleviate the global climate change by controlling environmental pollution raised by their generation on a large scale. However, the bottleneck problem of extensive pr...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章
doi:10.1186/s13068-020-1648-8
更新日期:2020-01-17 00:00:00
abstract::Lignin is the most abundant aromatic substrate on Earth and its valorization technologies are still under developed. Depolymerization and fragmentation are the predominant preparatory strategies for valorization of lignin to chemicals and fuels. However, due to the structural heterogeneity of lignin, depolymerization ...
journal_title:Biotechnology for biofuels
pub_type: 杂志文章,评审
doi:10.1186/s13068-019-1376-0
更新日期:2019-02-15 00:00:00